The present invention relates to a curing device employing light, especially for the polymerization of dental materials by light, comprising a hand-held device with light source that is connected by a cable to a supply station whereby the cable is detachable and can be plugged into the hand-held apparatus and the supply station. A control unit for the light source is provided in order to ensure a uniform light emission or intensity.
Various curing devices for curing by light are known which are mains-powered and which are used for the light-induced polymerization of dental materials. A hand-held apparatus receives the light source and connected by a cable to the supply station. Such curing devices have the advantage, in comparison to battery-operated curing devices, that a higher light output can be provided and that the hand-held apparatus itself is light-weight since the weight of the battery or accumulator has been eliminated.
In known curing devices the supply voltage for the light source in the supply station is stabilized in a manner known per se by a voltage controller. In these curing devices it is assumed that a voltage stabilization over the service life of the light source is sufficient in order to provide to sufficient light output for polymerization. In addition, it has been known to measure the light output of the hand-held apparatus whereby one example for such a light-curing device is known from German Gebrauchsmuster 92 12 892. In this curing device the supply station is provided with a light sensor which responds when the detected light is of sufficient intensity.
This solution however is disadvantageous because the action of monitoring whether the curing device still functions reliably is in the hands of the operator. Accordingly, different levels of responsibility on the user's part thus has a strong effect on the reliability of the device so that the manufacturers of such devices recommend to exchange the light source or lamp as a matter of precaution after about 100 hours of operating time.
Light sources which, for example, may be in the form halogen lamps are disposable items, However, there are considerable quality differences and thus differences in their service life. For example, for the same operating parameters, a lamp with a high-quality coil which is comprised of wire that is of uniform thickness and uniform roundness, may last three times longer than a light source of lower quality. However, whereby in known devices the improved service life of such high-quality light sources, which have also essentially a well defined spectrum, cannot be fully used for the aforementioned reasons.
A further disadvantage of such light curing devices is that they can be adapted only with difficulty to the local particularities of respective dental practices. While in some practices it is more favorable to arrange the supply station directly adjacent to the hand-held apparatus, such that a short cable is sufficient, in other practices the local particularities are such that an arrangement of supply station and of the hand-held apparatus spaced far apart is necessary.
These requirements of dental practices can be taken into consideration with known light curing devices only to a limited extent. The length of the cable may not surpass a certain limit in order not to impede the light intensity to be provided. On the other hand, the cable should not be too thick in order to provide the desired flexibility and bending ability so that in the past relatively limited minimum and maximum cable lengths have been provided. Furthermore, when supplying such curing devices, it must be specified which length of cable is desired in order to be able to adapt the light source control to the cable length. This must be performed by the manufacturer so that when the special requirements within the dental practice change or when it is determined that the initially ordered cable length is not sufficient, a complicated exchange with manipulations of the device by a service technician must be performed.
It is therefore an object of the present invention to provide a curing device of the aforementioned kind with improved economic use and greater flexibility with respect to its use.